Antifouling Biomimetic Liquid-Infused Stainless Steel: Application to Dairy Industrial Processing

Abstract

Fouling is a widespread and costly issue, faced by all food-processing industries. Particularly, in the dairy sector, where thermal treatments are mandatory to ensure product safety, heat-induced fouling represents up to 80% of the total production costs. Significant environmental impacts, due the massive consumption of water and energy, are also to deplore. Fouling control solutions are thus desperately needed, as they would lead to substantial financial gains as well as tremendous progress toward eco-responsible processes. This work aims at presenting a novel and very promising dairy fouling-mitigation strategy, inspired by nature, and to test its antifouling performances in real industrial conditions. Slippery liquid-infused surfaces were successfully designed directly on food grade stainless steel, via femtosecond laser ablation, followed by fluorosilanization and impregnation with an inert perfluorinated oil. Resulting hydrophobic surfaces (water contact angle of 112°) exhibited an extremely slippery nature (contact angle hysteresis of 0.6°). Outstanding fouling-release performances were obtained for these liquid-infused surfaces as absolutely no trace of dairy deposit was found after 90 min of pasteurization test in pilot-scale equipment followed by a short water rinse.

Atmospheric pressure plasma spraying of silane-based coatings targeting whey protein fouling and bacterial adhesion management

“…From this point, the focus will be taken on PL6, in order to elucidate the reasons for its good performances. (Figure 7B) and the presence of calcium in forms of particles ( Figure 7C) are consistent with previous observations of isothermal fouling [5,21].…”

“…calcium and protein ratio, ionic strength, pH [5,10,[14][15][16]) and by the surface properties (e.g. morphology, wettability, surface free energy [17][18][19][20][21]).…”

“…In the case of PL 6, this particular morphology, allied to the chemical features mentioned earlier, certainly lowered deposit adhesion and prevented interlocking of dairy foulant particles whose diameters are of 50-60 nm. Previous work indeed pointed out the importance of the relative size of surfacerelief versus foulants, suggesting that nano-roughness could be beneficial regarding fouling management[5,21].…”

Designing Liquid‐Infused Surfaces for Medical Applications: A Review

“…Other additive approaches involve non‐solvent‐induced phase separation and extraction processes, osmotically driven wrinkling, the electrodeposition of tungstite films, and chemical vapor deposition of silicon nanowires . Subtractive methods for creating surface structure have included the use of femtosecond laser ablation of steel (Figure B), titanium, plastic, or polymer, as well as acid etching on living enamel . Microscale water droplets evaporated off a polyphenylene oxide surface, termed breath figure patterns, represent yet another approach to creating large‐area textured surfaces .…”

Advanced Antiscaling Interfacial Materials toward Highly Efficient Heat Energy Transfer

“…To test its antifouling performances in real industrial conditions, SLIPS were successfully designed directly on food grade stainless steel (i.e., 316L 2B) by the combination of femtosecond laser ablation, fluorosilanization, and oil impregnation . Milk, like a lot of animal‐sourced foods, was elected as a fouling model liquid.…”